21011512243 has 8 divisors (see below), whose sum is σ = 21171069920. Its totient is φ = 20852432640.

The previous prime is 21011512199. The next prime is 21011512267. The reversal of 21011512243 is 34221511012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011512243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21011512283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31038 + ... + 207331.

It is an arithmetic number, because the mean of its divisors is an integer number (2646383740).

Almost surely, 2^21011512243 is an apocalyptic number.

21011512243 is a deficient number, since it is larger than the sum of its proper divisors (159557677).

21011512243 is a wasteful number, since it uses less digits than its factorization.

21011512243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239037.

The product of its (nonzero) digits is 480, while the sum is 22.

The spelling of 21011512243 in words is "twenty-one billion, eleven million, five hundred twelve thousand, two hundred forty-three".